Adjustable web tensioning apparatus



y 12, 1964 R. L. DAVIDSON 3,132,786

ADJUSTABLE WEB TENSIONING APPARATUS I Filed Oct. 16, 1962 INVENTOR RALPH L. DAVIDSON ATTORNEY United States Patent 3,132,786 ADJUSTABLE WEB TENSIONING APPARATUS Ralph L. Davidson, Southhoro, Mass, assignor to Curtis & Marble Machine Co., Worcester, Mass, a corporation of Massachusetts Filed Oct. 16, 1962, Ser. No. 230,948 6 Claims. (Cl. 226-111) This invention relates to a new and improved apparatus for tensioning and releasing tension with respect to a traveling web, the web passing over an initial driven roll into a processing machine as for instance for example a textile shear which requires a certain degree of tension on the web for proper operation thereof, the web then passing over a second driven roll adapted in general to be rotated slightly faster than the initial roll to preserve tension on the web being processed, the web then passing to a takeup roll which is driven at a slower rate than the intermediate or second roll, so as to relieve the tension just prior to winding or spooling the web.

The principal object of the invention in this case is to provide for varying the speed of the first or second roll so as to closely adjust the tension on the web as it is being processed while the machine is running and without the necessity of stopping the machine for this purpose as has been the custom in the prior art, thus resulting in considerable saving of time and also in more accurately pin-pointing, maintaining or adjusting the web tension under process as may be required as for instance by different speeds of operation overall, different kinds of textiles being operated upon, etc.

The invention further relates to arrangements and com binations of parts which will be hereinafter described and more particularly set forth in the appended claims.

Reference is to be had to the accompanying drawings, in which FIG. 1 is a view in side elevation illustrating the invention, and

FIG. 2 is a plan view with parts omitted illustrating the belt tensioning apparatus.

In order to illustrate the invention, there is shown in the drawings a machine which is provided with a framework generally indicated at 10. Of course this framework may assume any -form desired but in general it holds and supports most of the apparatus. The first roll of the three is the incoming driven roll 12. This is regarded as the initial roll for the web which is indicated at 14 and is wrapped about roll 12. Various guide-rolls, etc. may be provided for the processing mechanism which may be of any kind desired which requires the web 14 to be run under a certain degree of tension. The apparatus is particularly adapted as for instance to cloth shears. There is an outfeed roll at 16, this being (the second roll referred to and the third roll is the takeup roll 18, all of these rolls being driven. For the purpose of this disclosure, it may be assumed that rolls 18 and 16 are driven at fixed speeds, roll 18 being driven slower than roll 16 so that the section of the web which is indicated by the reference numeral 20 becomes slightly loose and is easily wrapped on the cloth roll 22; but roll 12 is driven at a slower speed than roll 16. All of the rolls being preferably covered with some kind of friction material, it will be clear that between roll 12 and roll 16 there Will be a definite pull or tension so that in the processing area which is generally indicated at the top of the framework of the machine by the reference numeral 24, the web 14 is under the required tension.

However it is necessary to vary the degree of this tension and of course if it can be varied accurately and minutely, the resulting product is of better quality, since 3,132,786 Patented May12, 1 964 the quality of operation of processing apparatus 24 depends in some part upon the degree of tension on the web; and if at the same time the adjustment .can be made without stoppingthe machine, a great deal of down time is clearly saved.

In order to provide such an adjustment, there is provided a hand wheel 28 which may be used to turn a shaft for instance at 30 and this hand wheel is positioned in convenient location for the operator so that the operator can utilize it when it becomes clear that a change in web tension is necessary or desirable. The shaft 60 is connected to a bell crank 32 pivoted at 34 to a part of the machine and carrying atone end of one of its arm a roller 36. It will be clear that as hell crank 32, is rotated on its pivot-pin 34, the pulley 36 will tighten or loosen a belt 38 with which pulley 36 is engaged.

Belt 38 is driven from a shaft 40 connected by any desired driving means or motor 42, andshaft 40 is uti lized by any driving means desired to drive the intermediate roll 16 as for instance by means of a belt 44 or the like, and in turn a pulley 48 on the roll shaft of roll 16 is utilized to drive the third or takeup roll 18, and as shown at a slower peripheral rate of speed than the roll 16.

The belt 38 is also engaged with a variable diameter pulley 50 of well known construction and design and this pulley drives a shaft 5-2 which in turn by for in stance belt 54 drives the shaft for the roll 12. Therefore when the wheel 28 is turned in the appropriate direction, the variable diameter pulley 50 will be operated upon to increase or decrease the speed of roll 12, and this of course in turn increases or decreases the tension on the web 14 between the two rolls 16 and 12 without in any way however effecting the relative speed of ro tation of rolls 16 and :18. Therefore the tension at the operating portion of the processing oprtion of the Web as at 24 is quickly and easily controlled by the operator while the machine is running and to a very minute degree, so that not only is the processing improved but a great deal of time is saved since the machine need not be stopped to make the adjustment.

Occasionally it becomes necessary to drive the in-feeding roll 12 slightly faster than the out-feeding roll 16 because of excess tension which may occur in the web and of course when this happens it is merely necessary to adjust the variable diameter of pulley 50 in the 0pposite way so as to achieve this result.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

'1. A web tensioning device for a processing machine having a frame and means on the frame to process a web passing through the machine, and there being three power driven rolls for feeding the Web through the machine including an initial roll feeding the web into the machine, a second or intermediate roll engaging the web and feeding it out of the machine, and a third or web takeup roll, means driving the power driven third roll at a less speed than the feed-out roll to relieve web tension between these two rolls, and means for adjusting the degree of tensionbetween the feed-in roll and the feed-out roll, said adjusting means including means for varying the peripheral speed of the feedin roll relative to that of the feed-out roll, and power means to drive the rolls, said power means normally driving the feed-out roll at a faster surface speed than the feed-in roll.

2. The device of claim 1 wherein said adjusting means comprises an adjustable speed changer and a handle therefor extending to an exterior point on the machine,

. 3 a the handle being connected to the speed changer and being operable at all times even with the machine running.

3. The device of claim 1 wherein the adjusting means includes a speed changer operative vto change the periph eral speed of the teed-in roll only, the peripheral speed of the feed-out roll being constant.

4. The device of claim 1 wherein the adjusting means includes a speed changer operative to change the speed of the .feed-in roll only, the feed-out roll speed being constant, and manual means to control the speed changer, said manual means including a hand wheel located at an exterior point of the frame of the machine.

5. The device of claim 1 wherein the adjusting means includes a speed changer operative to change the speed of the feed-in r011 only, the feed-out roll speed being constant, and manual means to control the speed changer, said manual means including a hand wheel located at an exterior point of the frame of the machine, a shaft conneoted to the hand wheel, a movable element operatively connected to the shaft to be actuated thereby, said ele ment being associated with the speed changer and controlling the same during the movement of the element.

6. A web tensionin-g device for a processing machine having a frame and means on the frame to process a web passing through the machine, and there being three power driven rolls for feeding the web through the machine including an initial roll feeding the Web into the machine, a second or intermediate roll engaging the web and feeding it out of the machine, and a third or web take-up roll, means driving the power driven third roll at a lesser peripheral speed than the feed-out roll to relieve web tension between these two rolls, and means for adjusting the degree of tension between the feed-in roll and the feed-out roll, said adjusting means including means for varying the peripheral speed of the feed-in roll relative to that of the feed-out roll.

References'Cited in the file of this patent UNITED STATES PATENTS 1,716,375 Fowler June 11, 1929 2,334,074 Coy Nov. 9, 1943 2,949,295 Huck Aug. 16, 1960 3,049,276 Wilkins Aug. 14, 1962 

6. A WEB TENSIONING DEVICE FOR A PROCESSING MACHINE HAVING A FRAME AND MEANS ON THE FRAME TO PROCESS A WEB PASSING THROUGH THE MACHINE, AND THERE BEING THREE POWER DRIVEN ROLLS FOR FEEDING THE WEB THROUGH THE MACHINE INCLUDING AN INITIAL ROLL FEEDING THE WEB INTO THE MACHINE, A SECOND OR INTERMEDIATE ROLL ENGAGING THE WEB AND FEEDING IT OUT OF THE MACHINE, AND A THIRD OR WEB TAKE-UP ROLL, MEANS DRIVING THE POWER DRIVEN THIRD ROLL AT A LESSER PERIPHERAL SPEED THAN THE FEED-OUT ROLL TO RELIEVE WEB TENSION BETWEEN THESE TWO ROLLS, AND MEANS FOR ADJUSTING THE DEGREE OF TENSION BETWEEN THE FEED-IN ROLL AND THE FEED-OUT ROLL, SAID ADJUSTING MEANS INCLUDING MEANS FOR VARYING THE PERIPHERAL SPEED OF THE FEED-IN ROLL RELATIVE TO THAT OF THE FEED-OUT ROLL. 